I don't keep either. I know my schedule for the most part, and if I have appointments, I rely on the appointment cards, which I keep on a magnetic board, or wait until the call that confirms my appointment.
I do both. I like seeing it in front of me a month at a time with all my appointments and schedules listed that I can glance at quickly. DHNI also have a shared calendar on our phones that we add our schedules in so we know what each other is doing and we don’t overlap anything that we need to do together.